Ever wonder why, when it comes to your favorite foods, one bite always leads to another? Why single-serving packages don't
stop you from eating the equivalent of one entire sleeve of chocolate chip cookies or a whole bag of potato chips?

Come on, you know why. Because it tastes so good.

But science has come up with yet another reason. When you eat because it's pleasurable and not because you're hungry, your
body activates chemicals that are linked to your brain's reward system. Yes, that's right -- just like drugs. Even worse,
when your reward system is activated, it overrides the chemical signals that tell your body that you're full. (Like we
need that.)

Italian researchers found this out when they tested eight adults who had already eaten and were full. They fed each of them
their own personal favorite foods and then fed them a less palatable food of equal calories. Then, they measured levels of 2-AG,
a chemical released by the brain's reward system, and the appetite-boosting hormone ghrelin. Both were elevated when the study
participants were chowing down on their favorite foods, but not when they were eating the other meal. (Read a synopsis of the
study here.)

That led scientists to raise the possibility that food can be an addiction in the same way drugs are. In fact, there are
ongoing studies looking at whether naltrexone, the medication that diminishes the appetite for certain recreational drugs,
may have the same effect on the appetite for food. (Learn more about how your brain chemistry can make you binge
here.)